Interleaved winding for electrical inductive apparatus

ABSTRACT

A transformer winding with coil disc sections having an odd number of conductor-turns per section. During construction, one section is wound with a pair of conductors to provide one less conductor-turn that is desired in that section. Another section is similarly wound with the same pair of conductors to provide one less conductor-turn than is desired. One of the conductors is then crossed-over to the previously wound section so that one conductor may be wound around each section for one additional turn. A splice joint in the previously wound section connects the conductor wound thereon to the proper conductor-turn.

United States Patent 1191 1111 3,781,739

Meyer Dee 25, 1973 INTERLEAVED WINDING FOR Primary ExaminerThomas J.Kozma ELECTRICAL INDUCTIVE APPARATUS Attorney-C. L. McHale et a1.

[75] Inventor: Lloyd E. Meyer, Greenville, Pa. [73] Assignee:Westinghouse Electric Corporation, [57] ABSTRACT Pittsburgh, Atransformer winding with coil disc sections having [22] Filed: Man 281973 an odd number of conductor-turns per section. During construction,one section is wound with a pair of con- PP 345,813 ductors to provideone less conductor-turn that is desired in that section. Another sectionis similarly 52 vs. C! 336/70 29/605 336/187 Wound with the Same PalirOf chdhctts to Provide 51 Int. Cl. 1161: 15/14 one less that is desiredone of the 58 Field of Search 336/69 70 186 cohductt is t0 thePtevtttusty 3 wound section so that one conductor may be wound aroundeach section for one additional turn. A splice [56] References Citedjoint in the previously wound section connects the conductor woundthereon to the proper conductor- FOREIGN PATENTS OR APPLICATIONS tum1,132,803 0/0000 Great Britain 336/187 I 4 Claims, 12 Drawing Figures 5A 60 T r-lBB A487 A3 B6 A2 B5 A1 B4 A0 62 76 \70 A4 B0 A5 Bl A6 B2 A7 B3A8 B4 64 /78 A72 B7 A3 B6 A2 B5 Al B4 A0 B3 66 A3 B0 A4 B1 A5 B2 A6 B3A7 L INTERLEAVED WINDING FOR ELECTRICAL INDUCTIVE APPARATUS BACKGROUNDOF THE INVENTION 1. Field of the Invention This invention relates, ingeneral, to electrical inductive apparatus and, more specifically, tointerleaved windings for power transformers.

2. Description of the Prior Art Interleaving the conductors of windingsfor power transformers is very useful for improving the surge voltagecharaceristics of the winding. One type of interleaved winding is thetwo-conductor mutually twin interleaved winding. In this type ofwinding, two conductors provide conduction paths which are interleavedthrough two coil disc sections. The interleaving pattern is repeated ineach pair of disc sections.

The conductors of the twin interleaved winding are wound together sincethey parallel each other throughout the winding. Since the conductorsare wound together, and since each revolution of the winding tube duringthe winding process increases the number of conductor-turns in the discsection by two, such windings are limited to coil disc sections havingan even number of conductor-turns.

It is desirable, for several reasons, to be able to wind interleavedcoil disc sections having an odd number of conductor-turns therein. Thenumber of conductorturns between tap positions is usually determined bythe transformer design. If an even number of conductor-turns isnecessary for proper tapping between the disc sections, one section musthave more turns than the other section according to the prior art. Forexample, if the total number of conductor-turns for two sections must be30, one section must have 16 conductorturns and the other section musthave 14 conductorturns.

Variations in the radial build of disc sections presents windingproblems, reduces the mechanical strength of the winding structure,affects the impedance of the transformer, and provides other detrimentaleffects. Therefore, it is desirable, and it is an object of thisinvention, to provide'a conveniently-wound twin interleaved windingwhich has an odd number of conductorturns per coil disc section.

SUMMARY OF THE INVENTION There is disclosed herein a new and usefulinterleaved transformer winding with coil disc sections having an oddnumber of conductor-turns and amethod of constructing same. The windingincludes two conductors which are spirally wound through each'coil discsection of the winding. The two conductors are first woundsimultaneously to form one disc section having an even number ofconductor turns. The two conductors are also wound simultaneously toform another disc section having an even number of conductor-turns. Oneof the conductors is crossed-over to the previously wound section andboth sections are wound with one more turn of the conductor thereon. Theconductor around the previously wound section is cut and joined to oneof the conductor-turns of that section. With the use of this invention,coil disc sections may be provided which have an odd number ofconductor-turns per section. The disc sections are provided withoutcomplicated winding procedures or an excessive number of conductorsplices.

BRIEF DESCRIPTION OF THE DRAWING Further advantages and uses of thisinvention will become more apparent when considered in view of thefollowing detailed description and drawing, in which:

FIG. 1 is a partial view of a transformer core having a coil discsection disposed therearound;

FIG. 2 is a schematic diagram of an interleaved winding constructedaccording to the prior art with each section having an even number ofconductor-turns;

FIG. 3 is a schematic diagram of an interleaved winding constructedaccording to one embodiment of this invention;

FIG. 4 is a schematic diagram of an interleaved winding constructedaccording to another embodiment of this invention;

FIGS. 5 through 11 are views illustrating steps performed in winding apair of coil disc sections according to this invention; and

FIG. 12 is a partial view of the outer turns of a pair of coil discsections constructed according to this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Throughout the followingdescription, similar reference characters refer to similar elements ormembers in all the figures of the drawing.

Referring now to the drawing, and to FIG. I in particular, there isshown a section of a transformer core 10 with a winding structure 12disposed thereon. The winding structure 12 includes the low-voltagewinding 14 which is supported from the core 10 by the spacers 16, awinding tube 18, and a high-voltage winding 20 which is wound around thewinding tube 18.

FIG. 1 illustrates one coil disc section 22 of the winding 20. The discsection 22 is formed by strap conductors 24 and 26 which are disposedradially adjacent to each other throughout the disc section 22. Thefinish ends 28 and 30 of the conductors 24 and 26 are located on theoutside of the disc section 22. The start ends 32 and 34 of theconductors 24 and 26 are located on the inside of the disc section 22.This invention relates to the arrangement of the conductors in discsections such as section 22, and to the method of winding such sections.

FIG. 2 illustrates schematically an interleaved winding structure 36having at least four coil disc sections 38, 40, 42 and 44. Start-startconnections 46, 48 and 50 and finish-finish connections 52, 54 and 56interconnect the various coil disc sections. Line leads 58 may beappropriately connected to other disc sections or to the line terminalsof the winding 36.

The winding 36 is formed from conductors A and B which are woundtogether as a conductor pair. Each conductor-turn in FIG. 2 is denotedby a letter and number. The letter represents the conductor which formsthe conductor-turn, and the number represents the number of electricalturns, and hence the relative voltage, between the conductor-turns ofboth conductors.

By conventional representation, FIG. 2 illustrates the start and finishends of the conductors. Thus, in each coil disc section, there isillustrated two more conductor-turns than the number of actualelectrical turns of each conductor in the section. In each coil discsection of FIG. 2, there are electrically four turns each comprising twoconductors. This type of representation will also be used in describingand claiming the embodiments of this invention.

According to the prior art, disc sections interleaved in the mannerillustrated in FIG. 2 have contained an even number of conductor-turns.FIG. 2 illustrates ten conductor-turns per section. Since the conductorsA and B are always wound together according to the prior art, variationsin the radial build of a section could only be accomplished in intervalsof two conductors. Without excessive splices or joints in the conductorsA and B, an odd number of conductor-turns could not be wound into thecoil disc sections according to the prior art.

FIG. 3 represents schematically an interleaved winding 60 having discsections with both an even and an odd number of conductor-turns. Coildisc sections 62 and 64 contain an even number of conductor-turns andcoil disc sections 66 and 68 contain an odd number of conductor-turns.The finish-finish connections 70, 72 and 74 are made by a continuousconductor and without any splices or joints between the disc sections.The finish-finish connections 70, 72 and 74, together with thestart-start connections 76, 78 and 80, provide the same type ofinterleaving of the conductors as exists in the winding 36 shown in FIG.2.

FIG. 4 represents schematically an interleaved winding82 in which thecoil disc sections 84, 86, 88 and 90 each contain an odd number ofconductor-turns. Development, or progression, of the conduction pathsprovided by conductors A and B can be determined by following theletter-number designators for each conductor-turn. The start-startconnections 92, 94 and 96 the finish-finish connections 98, 100 and 102provide the same type of interleaving as shown in FIG. 2, but with anodd number of conductor-turns per coil disc section.

Other winding arrangements using the teachings of this invention arepossible and' are within the contemplation of this invention. Inaddition, the conduction paths furnished by the conductors A and B arenormally connected together at the ends of the winding to effectivelyplace the paths in parallel.

FIGS. through'll illustrate steps performed in the construction of apair of coil disc sections having an odd numer of conductor-turnstherein. For convenience in indicating the position of the conductors inthe disc sections, the sections wound in the illustrations of FIGS. 5through 11 generally represent the coil disc sections 84 and 86 shown inFIG. 4.

As shown in FIG. 5, the conductors A and B are pulled from the spools104 and 106, respectively. Conductor B is positioned on the winding tube18 beneath conductor A. Suitable clamping means, which are notillustrated, may be used to secure the conductors to the winding tube18. When winding other than the first coil disc section onto the windingtube 18, clamping means may not be required since at least one of theconductors will be attached to the previously wound section. Normally, aportion of at least one conductor from a previously wound disc sectionis positioned under the conductors A and B for later connection to acoil disc section which is to be formed by the conductors. However, thisconductor connection is not illustrated for 6 clarity of the figures.

The winding tube 18 is rotated in the direction indicated by the arrow105 a sufficient number of times to provide one less radially disposedconductor-turn than is desired in the finished section 84. The windingtube 18 would be rotated three times for the coil disc section 84. FIG.6 illustrates the partially wound disc section 84. Conductor B is cutand the connection 94 is properly shaped for splicing to anotherconductor-turn developed later in the construction process.

The pre-wound" coil disc section 84 is then broken down and hand-wound"into section 84" as shown in FIG. 7. This procedure inverts the coil, orplaces the last wound conductor-turns near the inside of the section84". I

Conductor A is then moved to the position where the next coil discsection is to be wound as shown in FIG. 8. This also forms thestart-start connection 92. Conductor B is positioned on top of conductorA and is normally connected to the conductor connection which was notillustrated in the interest of clarity. The winding tube 18 is thenrotated to wind the conductors into coil disc section 86' as shown inFIG. 9. As with the winding of section 84, the winding tube 18 would berotated a sufficient number of times to provide one conductor turn lessthan the number of conductorturns desired in the finished section 86. Inthis specific embodiment, of the invention, the winding tube 18 would berotated three times in the direction indicated by the arrow 105. I I

The conductor B is then crossed-over onto section 84" as shown in FIG.10. This procedure establishes the finish-finish connection 98. Thewinding tube 18 is then rotated one more turn in the direction 105 towind the conductor B one conductor-turn around the coil disc section 84"and the conductor A one conductorturn around the coildisc section 86'.The result is illustrated in FIG. 11. Conductor Bis cut and the endthereof is spliced or joined to the next conductor-turn of conductor Bat position 110. This completes the conduction path through the coildisc sections 84 and 86 of conductor B. The spacing of the sections 84and 86 is exaggerated in FIG. 11 to show the interconnections. Normally,section 86 is wound closer to section 84 and is separated therefrom bypressboard radial spacers.

FIG. 12 is a partial view of the outer conductor-turns of the coil discsections 84 and 86. The conductor-turns are labeled with thecorresponding characters shown in FIG. 4. The conductor-turns B3 and B4are joined together at position by a suitable welding or brazingoperation. The conductor-turns B3 and B4 may be overlapped for a shortdistance to facilitate the joining operation.

Transformer windings constructed according to this invention, preferredembodiments of which are dis closed herein, conveniently contain an oddnumber of conductor-turns in their coil disc sections. Since numerouschanges may be made in the above-described apparatus and method, andsince different embodiments of the'invention may be made withoutdeparting from the spirit thereof, it is intended that all of the mattercontained in the foregoing description or shown in the accompanyingdrawing, shall be interpreted as illustrative rather than limiting.

I claim as my invention:

1. A winding for electrical inductive apparatus, comprising:

flrst and second electrical conductors;

at least first and second coil disc sections each disposed at differentaxial positions in the winding,

each of said coil disc sections having a plurality of radially disposedturns of said conductors forming conductor-turns with each of said coildisc sections having an odd number of total conductor-turns,

start and finish conductor-turns in said first coil disc section formedby the same conductor in that section;

start and finish conductor-turns in said second coil disc section formedby the same conductor in that section;

start-start and finish-finish connections which interconnect said coildisc sections; and

a conductor-turn connection joint which connects together the finishconductor-turn of one of said coil disc sections with the nextconductor-turn of the same conductor in the same coil disc section.

2. The winding of claim 1 wherein the first and second electricalconductors are interleaved to form first and second conduction paths,respectively;

said first conduction path progressing in a first radial directionthrough the first coil disc section, then in a second radial directionthrough the second coil disc section;

said second conduction path progressing in the second radial directionthrough the second coil disc section, then in the first radial directionthrough the first coil disc section;

said first radial direction being opposite to said second radialdirection.

3. A method of providing an odd number of conductor-turns in first andsecond interleaved coil disc sections of a transformer winding,comprising the steps of:

winding each first and secondcoil disc section with an even number ofconductor-turns from first and 10 comprising the steps of:

positioning a first conductor on a winding tube;

positioning a second conductor on top of the first conductor;

rotating the winding tube an even number of times to form a first coildisc section;

separating the second conductor from the first coil disc section;

breaking down and hand-winding the first coil disc section;

placing the second conductor over the first conductor and rotating thewinding tube an even number of times to form a second coil disc section;

moving the second conductor to the outside of the first coil discsection;

rotating the winding tube substantially one additional turn to wind oneconductor on each coil disc section;

separating the second conductor from the last conductor-turn of thefirst coil disc section; and

joining together the last conductor-turn of the first coil disc sectionand the next conductor-turn of the second conductor in the first coildisc section.

1. A winding for electrical inductive apparatus, comprising: first andsecond electrical conductors; at least first and second coil discsections each disposed at different axial positions in the winding, eachof said coil disc sections having a plurality of radially disposed turnsof said conductors forming conductor-turns with each of said coil discsections having an odd number of total conductor-turns, start and finishconductor-turns in said first coil disc section formed by the sameconductor in that section; start and finish conductor-turns in saidsecond coil disc section formed by the same conductor in that section;start-start and finish-finish connections which interconnect said coildisc sections; and a conductor-turn connection joint which connectstogether the finish conductor-turn of one of said coil disc sectionswith the next conductor-turn of the same conductor in the same coil discsection.
 2. The winding of claim 1 wherein the first and secondelectrical conductors are interleaved to form first and secondconduction paths, respectively; said first conduction path progressingin a first radial direction through the first coil disc section, then ina second radial direction through the second coil disc section; saidsecond conduction path progressing in the second radial directionthrough the second coil disc section, then in the first radial directionthrough the first coil disc section; said first radial direction beingopposite to said second radial direction.
 3. A method of providing anodd number of conductor-turns in first and second interleaved coil discsections of a transformer winding, comprising the steps of: winding eachfirst and second coil disc section with an even number ofconductor-turns from first and second conductors disposed radiallyadjacent to each other; moving the second conductor from the second tothE first coil disc section; and winding substantially one additionalturn of the second conductor around the first coil disc section and thefirst conductor around the second coil disc section.
 4. A method ofconstructing an interleaved winding, comprising the steps of:positioning a first conductor on a winding tube; positioning a secondconductor on top of the first conductor; rotating the winding tube aneven number of times to form a first coil disc section; separating thesecond conductor from the first coil disc section; breaking down andhand-winding the first coil disc section; placing the second conductorover the first conductor and rotating the winding tube an even number oftimes to form a second coil disc section; moving the second conductor tothe outside of the first coil disc section; rotating the winding tubesubstantially one additional turn to wind one conductor on each coildisc section; separating the second conductor from the lastconductor-turn of the first coil disc section; and joining together thelast conductor-turn of the first coil disc section and the nextconductor-turn of the second conductor in the first coil disc section.